Industrial processes often require to conveyance of fluids through piping networks as part of normal manufacturing operations. These piping networks often carry noxious or toxic fluids, (e.g., ammonia, chlorine, etc.) through areas in manufacturing plants where people are regularly present. Inadvertent exposure to these fluids, whether in the form of gases or liquid, may prove harmful or irritating to such people and the environment, may disrupt manufacturing processes and may contaminate work-in-process or finished product. As a result, numerous detection and containment systems are believed to have been developed in the prior art to sense, purge, collect and discharge potentially harmful leaked fluids from manufacturing facilities.
For example, U.S. Pat. No. 4,711,096 ("Leak Detection and Refrigerant Purge System") appears to disclose a system for sensing gaseous ammonia leaks in commercial refrigeration systems, and for automatically collecting and venting such leaked ammonia away from the refrigerated environment. This is apparently intended to avoid contamination of the stored product, and to reduce the possibility of human exposure to gaseous ammonia suspended in the air.
In practice, dilution and collection systems are believed to simply collect the leaked fluids, and to vent the same directly into the air outside the operating facility at a location distant from both product and people (e.g., on the roof of a plant, at a remote end of a building, etc.). These systems, however, generally do not detoxify or neutralize the leaked fluid before being vented into the air.
For example, ammonia refrigerant (NH.sub.3) has a molecular weight (i.e., 17) significantly less than that of ambient air (i.e., 29). Thus, gaseous ammonia vented into the air will remain suspended in the air, and may migrate unpredictably to surrounding areas, possible creating a noxious and potentially harmful situation. In some cases, venting of the gaseous ammonia directly into the air may result in an emergency response from local fire and police departments in an attempt to prevent further migration of the un-neutralized ammonia gas into sewers and populated areas. In general, ammonia (NH.sub.3) reacts with water (H.sub.2 O) to form what is typically referred to as "household liquid ammonia" (NH.sub.4 OH). Household ammonia, although odorous, is not generally harmful unless orally ingested or subjected to variations in pressure or temperature. However, the response of local police and fire departments is often accompanied by attempts to "wash" or neutralize the escaped ammonia gas with water sprayed by fire hoses. As a practical matter, the discharged gaseous ammonia and the location of the outlet vent are simply sprayed with a large volume of water in the hope of neutralizing the gaseous ammonia prior to further migration through the air. Although such neutralizing or "washing" of ammonia with water is theoretically a sound response, the method of response is generally inefficient. For example, even assuming that an ammonia leak is promptly detected, there is time lag between the time the ammonia begins to escape and the appearance by the local or facility fire departments on the scene. In other words, the response normally comes after substantial quantities of refrigerant have been leaked, and have possibly migrated to an area distant from the source of the emission. Secondly, uncontrolled or unmeasured spraying with water of the outlet vent, the surrounding air or a migrating gaseous ammonia cloud, is typically inefficient, and will likely not result in complete neutralization of the vented ammonia. Third, rather than the desired product of the neutralization reaction (i.e., NH.sub.4 OH) being concentrated and contained in a relatively small area immediately around the outlet vent, such reaction product as is formed will be typically spread over a much wider area, depending upon the extend and severity of the leak, the lag in the emergency response time, and the effectiveness of the response.
Upon information and belief, the prior art has recognized these problems, but no known solution has proved to be adequate. For example, one known solution is to provide a containment tank filled with water and through which leaked ammonia gas is passed. These tanks, possibly containing on the order of 20,000 to 30,000 gallons of water, are bulky, unsightly, and often expensive. Moreover, care must be taken to maintain the integrity of the tank and the volume of water therein, which must be proportional to the maximum possible ammonia leakage in order to be effective. Moreover, appurtenant mechanical systems (e.g., piping, pumps, sight gauges, and the like) supporting the tank must be maintained. In addition to these factors, the tanks are also subject to temperature elevation with leakage of even small quantities of ammonia. For example, neutralization of ammonia to a 10% solution by weight may result in an evaluation of water temperature of over 100.degree. F. Moreover, at higher temperatures, the solubility of ammonia in water decreases, presenting the question of whether the volume of water in the tank is adequate to react with the leaked ammonia at the elevated temperatures. In addition, intimate thoroughly-mixed contact between the ammonia and water is critical for complete neutralization to occur. A simple inlet at a tank bottom may result in ammonia bubbles rising upwardly to the water surface without complete neutralization or interaction. This can lead to an uncombined ammonia layer at the surface of the water. As a result, pressure build-up and possible explosion, as well as gaseous ammonia being leaked into the atmosphere, remain as possibilities.
Thus, the known prior art is believed to have failed to adequately resolve the need for a simple and inexpensive, yet reliable system for effectively neutralizing leaks of noxious or toxic fluids without undue delay.